JP2003156901A - Endless belt, belt drive system, image forming apparatus and endless belt production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt that eliminates detriment to a skew prevention function which is caused by peeling or displacing of skew guides 1a and a cost increase, which results from a process for fixing the skew guides 1a and to provide a belt drive system using the belt, an image forming apparatus, and a belt production method for producing the endless belt. SOLUTION: In the endless belt in which the skew prevention guides 1a projecting from the peripheral face of the belt are provided near the belt edges widthwise, the skew guides 1a are integrally and seamlessly formed from a material that is the same as the belt main body by a centrifugal molding method. This belt is used as the photoreceptor belt, intermediate transfer belt, paper carrying belt, fixing belt, etc., of the image forming apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless belt, a belt driving device using the same, an image forming apparatus, and a method for manufacturing the endless belt.

[0002] Conventionally, an endless belt, which is endlessly moved while being supported by a supporting roller as a supporting member, has been used in various fields. For example, in an electrophotographic image forming apparatus, an endless belt may be used as a latent image carrier, an intermediate transfer member, a paper conveying member, or the like. The electrophotographic image forming apparatus forms an image by the following process. That is, first, a latent image carrier such as a photoconductor is exposed and scanned to form an electrostatic latent image thereon, and a developer such as toner charged negatively or positively is attached to the latent image carrier to obtain a visible image. Next, the visible image is transferred from the latent image carrier to a transfer body such as transfer paper, or transferred through an intermediate transfer body, and then fixed on the transfer body by heating or the like. In such a process, an endless belt is used as a latent image carrier, an intermediate transfer member, a paper carrying member for carrying a transfer paper, and the like.

The endless belt is endlessly moved by rotationally driving at least one support roller while its inner peripheral surface is supported by a plurality of support rollers. In such endless movement, if the circularity of the support rollers is not sufficiently obtained, or if the straightness and the parallelism are slightly deviated among the plurality of support rollers, the endless belt is caused to travel to one side. Detach or damage the support roller.

[0004]

[Patent Document 1] Japanese Patent Laid-Open No. 04-
190280, JP 2000-1237,
Japanese Patent Application Laid-Open No. 2000-289823 proposes an image forming apparatus using an endless belt provided with offset guides as protrusions at both ends of the inner peripheral surface of the belt. In these endless belts, a detent guide is fixed to both ends of the inner circumferential surface of the belt with an adhesive or the like over the entire circumference of the belt. When the support roller is tilted or the like to try to shift to one side, the side stop guide on the side opposite to the side to be brought into contact with the end surface of the support roller prevents further deviation. However, if the environment becomes hot and humid or the adhesive deteriorates, the adhesive part of the anti-slip guide may be partially peeled or misaligned, and the offset prevention function may not be fully fulfilled. was there. Further, in addition to the step of forming the endless belt, the step of fixing the offset guides to both ends of the inner peripheral surface of the belt is required, which causes a problem of reducing productivity and increasing cost. .

These problems occur in an image forming apparatus using an endless belt provided with a detent member, but similar problems may occur in an apparatus using an endless belt having such a structure.

The present invention has been made in view of the above background, and an object of the present invention is to reduce the deviation preventing function due to peeling or deviation of the deviation preventing guide and to fix the deviation preventing guide. By providing an endless belt capable of eliminating both the cost increase due to carrying out the process for and a belt driving device using the same, an image forming apparatus, and a belt manufacturing method for manufacturing the endless belt. is there.

[0007]

In order to achieve the above object, the invention of claim 1 is an endless belt in which a projecting portion projecting from the belt peripheral surface is provided at or near an end portion in the belt width direction. The protrusion is integrally formed of the same material as the belt body. Also,
The invention of claim 2 is the endless belt of claim 1, wherein at least one of elastic rubber and thermoplastic elastomer is
It is characterized by being included in the material.

In these endless belts, the protrusions provided at or near the ends of the inner peripheral surface of the belt in the belt width direction function as a detent guide. The protrusion is made of the same material as the belt body and is integrally formed without a seam. Therefore, the deterioration of the adhesive does not cause peeling or deviation from the belt body, and it is possible to eliminate the deterioration of the deviation prevention function due to peeling or deviation. Moreover, since the step of fixing the belt body is not necessary, the cost increase due to the execution of the step can be eliminated.

According to a third aspect of the present invention, in the belt drive device for moving the endless belt endlessly while supporting the endless belt by a plurality of supporting members on the inner peripheral surface of the belt, the endless belt according to the first or second aspect is used. It is characterized by.

According to this belt driving device,
Alternatively, by using the endless belt of No. 2, it is possible to eliminate the one-sided running of the endless belt due to the peeling or deviation of the anti-slip guide.

According to a fourth aspect of the present invention, a latent image bearing member carrying a latent image, a developing means for developing the latent image on the latent image bearing member,
Belt drive means for endlessly moving the endless belt so as to pass through a position facing the latent image latent image carrier, and a visible image developed by the developing means from the surface of the latent image carrier at the facing position. In the image forming apparatus including a transfer unit that transfers toward the endless belt side, as the endless belt,
It is characterized by using the thing of Claim 1 or 2.

In this image forming apparatus, the visible image on the latent image carrier is transferred to the endless belt or the transfer body conveyed to the endless belt. If the endless belt is made to run to one side during this transfer, the transfer image may be disturbed by rubbing the endless belt or the transfer body conveyed to the endless belt with the latent image carrier. However, in this image forming apparatus, since the endless belt according to claim 1 or 2 that can eliminate the offset running caused by the peeling or deviation of the offset guide is used, the transfer image is disturbed due to the offset running. Can be resolved.

According to a fifth aspect of the present invention, a latent image carrying belt for carrying a latent image while moving endlessly, a developing means for developing the latent image on the latent image carrying belt, and a latent image carrying belt for developing the latent image are developed. In the image forming apparatus including the transfer means for transferring the visible image to the transfer body, the endless belt according to claim 1 or 2 is used as the latent image carrying belt.

In this image forming apparatus, the visible image on the latent image carrying belt which is an endless belt is transferred to a transfer body such as an intermediate transfer body or a transfer paper. If the latent image carrying belt is run to one side during this transfer, there is a risk that the latent image carrying belt and the transfer body may rub against each other to disturb the transferred image. However, in this image forming apparatus, since the endless belt according to claim 1 or 2 that can eliminate the offset running due to the peeling or deviation of the offset guide is used as the latent image carrying belt, the offset running causes the offset running. Disturbance of the transferred image can be eliminated.

According to a sixth aspect of the present invention, a latent image carrying member carrying a latent image, developing means for developing the latent image on the latent image carrying member into a visible image, and the visible image being transferred. 3. An image forming apparatus having a fixing unit for fixing the visible image on the transfer body while conveying the transfer body by the endless belt, wherein the endless belt according to claim 1 or 2 is used. It is what

In this image forming apparatus, the visible image is transferred from the latent image carrier to the transfer body, and the visible image is fixed on the transfer body while being conveyed by the endless belt in the fixing means. Excuse me. The visible image immediately before fixing is in a state in which the developer that constitutes it is likely to rub off.Therefore, if the endless belt is eccentrically run during fixing, the image will be rubbed by the transfer member and the heating roller. May be disturbed. However, in the present image forming apparatus, since the endless belt in the fixing unit uses the one according to claim 1 or 2, which can eliminate the offset running due to the peeling or deviation of the offset guide, the endless belt is used for the offset running. It is possible to eliminate the disturbance of the image due to the fixing.

According to a seventh aspect of the present invention, in the method for producing an endless belt, the endless belt is provided by a centrifuge molding method, wherein the endless belt having the protruding portion protruding from the circumferential surface of the belt is provided at or near the end portion in the belt width direction. As a cylindrical mold for
The present invention is characterized in that an inner peripheral surface of a mold provided with a groove-shaped recess extending in the rotational direction is used, and the protrusion is integrally molded with the same material as the belt main body by the groove-shaped recess. Further, the invention of claim 8 is characterized in that, in the belt manufacturing method of claim 7, the endless belt membrane after centrifugal molding is turned upside down. The invention according to claim 9 is characterized in that, in the belt manufacturing method according to claim 7 or 8, the mold is used in which the opening width of the groove-shaped recess is equal to or larger than the groove bottom width.

In these belt manufacturing methods, the groove-shaped recess provided in the mold for centrifugal molding causes the protruding portion extending in the belt circumferential direction at or near the end in the belt width direction to be the same as the endless belt body. The material can be integrally molded. The endless belt after demolding has the protruding portion on the outer peripheral surface of the belt, but when it is turned upside down, it is positioned on the inner peripheral surface of the belt and functions as a detent guide. The endless belt according to claim 1 or 2 is manufactured. Therefore, in the present belt manufacturing method, an endless belt that eliminates both a decrease in the offset prevention function due to peeling and displacement of the offset guide and an increase in cost due to the step of fixing the offset guide is eliminated. Can be manufactured.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an endless belt to which the present invention is applied will be described below. FIG. 1 is a perspective view showing an endless belt according to this embodiment. In the figure, the endless belt 1 is a seamless belt that is seamless in the circumferential direction, and anti-shift guide portions 1a that are protrusions are formed near both ends in the width direction. This anti-slip guide portion 1a is
It projects in a convex shape from the inner circumferential surface of the belt so as to extend in the circumferential direction of the belt, and is seamless in the circumferential direction like the belt body. Further, there is no joint between the belt body and the belt body, and the belt body is made of the same material and integrated. The endless belt 1 having such a configuration is different from the one in which the detent guide is fixed to the belt main body with an adhesive or the like.
A situation in which the anti-slip guide portion 1a is not peeled off or displaced from the belt main body due to deterioration of an adhesive or the like does not occur.

The endless belt 1 shown in FIG. 1 is formed by a belt manufacturing method using a centrifugal molding method (sometimes referred to as a centrifugal molding method). FIG. 10 is a sectional view showing a conventional mold used in the centrifugal molding method together with a discharge nozzle. In the figure, a mold 2 for centrifugal molding is formed in a cylindrical shape, and two dam members 2a projecting in a ring shape are provided on the inner peripheral surface thereof near both ends in the cylinder axis direction. The discharge nozzle 3 disposed inside the mold 2 constitutes a part of the centrifugal molding device together with the mold 2. This centrifugal molding apparatus is provided with the following means in addition to the mold 2 and the discharge nozzle 3. That is, a nozzle moving means for horizontally moving the discharge nozzle 3, a rotating means for rotating the die 2 about a chain line (cylinder center axis) in the drawing, and a rotational speed adjusting means for adjusting the rotational speed of the die 2 by the rotating means. Feeding means such as a metering pump or a compression pump for feeding the belt material fluid to the discharge nozzle 3,
It is a flow path switching means such as a dispenser for switching the fluid supply flow path to the feeding means, a solidification means for solidifying the belt material fluid in the mold 2 by heating or blowing (neither is shown). The belt material fluid is a fluid that can be solidified by heating or blowing air, and exhibits mechanical strength capable of functioning as an endless belt by solidification.

The liquid sending means sends the belt material fluid supplied from the flow path switching means to the discharge nozzle 3. The discharge nozzle 3 is moved in the horizontal direction (arrow direction) in the drawing by the nozzle moving means, and the belt material fluid sent from the sending means is rotated at a low speed such as 100 [rpm] by the rotating means. Spraying or jetting (hereinafter, simply referred to as supply) toward the inner peripheral surface of the mold 2 being pressed. The nozzle moving means uses the weir member 2a on the left side in the drawing and the weir member 2a on the right side in the drawing by the belt material fluid.
The discharge nozzle 3 is horizontally moved so as to be supplied to the inner peripheral surface of the mold 2 between and. As a result, the belt material fluid is supplied to the entire area between the two dam members 2a. In addition, instead of rotating the mold 2, the discharge nozzle 3 that moves in the horizontal direction in the drawing is used.
The belt material fluid may be supplied to the inner peripheral surface of the mold 2 while rotating.

When the supply of the belt material fluid to the inner peripheral surface of the mold 2 is completed, the mold 2 is then moved to, for example, 10 by the rotating means.
While rotating at a high speed such as 00 [rpm], the belt material fluid on the inner peripheral surface is subjected to a blowing process or a heating process by the solidifying means. Then, the belt material fluid spreads with a uniform thickness between the two dam members due to the centrifugal force generated by the high-speed rotation of the mold 2, and the reactions such as drying, polymerization, and curing are caused by the air blow treatment or the heat treatment (for example, 100 ° C.). It is accelerated and solidifies. And it becomes an endless belt film. The inner peripheral surface (the surface not in contact with the mold) of the endless belt film has excellent smoothness by spreading and solidifying the belt material fluid with a uniform thickness. Further, since the outer peripheral surface side is solidified while being pressed against the mold 2 by the centrifugal force, it has the same smoothness as the inner peripheral surface of the mold 2. The high rotational speed of the mold 2 is such that the specific gravity (density) of the belt material fluid, the viscosity, the supply amount, the size of the mold 2 (radial distance in the mold 2), etc., so as to realize the formation of such an endless belt film. It is set according to. When the two dam members 2a are not provided, as shown in FIG. 11, the end portion of the belt material fluid on the inner peripheral surface of the mold 2 is thinly dripping, and the endless belt membrane after solidification is molded. In some cases, it may be difficult to peel it from 2. Although the provision of the two dam members 2a eliminates such a problem, the dam member 2a may not be provided depending on the thickness of the belt and the properties of the belt material fluid.

Two dam members 2a arranged on the inner peripheral surface of the mold 2.
Can be attached to and detached from the mold 2 by, for example, a magnet or an engagement mechanism. For the endless belt membrane obtained by solidifying the belt material fluid, these two dam members 2
After removing a, it is peeled from the mold 2. By removing the dam member 2a and exposing the end surface of the endless belt film, a force for peeling is applied to the end surface, or the endless belt film and the mold 2 are exposed.
Since a scraper can be inserted between the inner peripheral surface and the inner peripheral surface, the endless belt membrane can be easily peeled off. Further, in order to facilitate peeling, a mold release agent such as oil may be applied to the inner peripheral surface of the mold 2 before supplying the belt material fluid. Further, when a belt material fluid that is hardened by further heating or drying after solidification is used, peeling is facilitated by terminating the treatment before completely hardening. However,
In this case, it is necessary to complete the curing by heating the endless belt film after peeling. When forming the multi-layered endless belt 1 formed of different materials, the belt material fluid including the lower layer material formed on the innermost side (inside the hoop) is solidified on the inner peripheral surface of the mold 2 to form a single layer. After obtaining the endless belt film, the endless belt film made of another material is sequentially formed on the endless belt film, and then the obtained multilayer endless belt film may be peeled off.

The above is the outline of the conventional belt manufacturing method. The endless belt 1 according to the present embodiment shown in FIG. 1 is centrifugally molded using a mold 2 having a configuration different from the conventional one. FIG. 2 is a sectional view showing a mold used for centrifugal molding of the endless belt 1 according to the present embodiment together with a discharge nozzle. In FIG. 2, on the inner peripheral surface of the mold 2, two groove-shaped concave portions 2b located between the two dam members 2a facing each other.
Are formed. These two groove-shaped recesses 2b are formed so as to extend over the entire area of the mold 2 in the circumferential direction in the vicinity of the dam members 2a which are different from each other.

While rotating the mold 2 having such a structure at a low speed,
As shown in FIG. 4, the discharge nozzle 3 that moves horizontally as shown in FIG. 3 supplies the belt material fluid F to the entire area between the two dam members 2a on the inner peripheral surface of the mold 2 and then rotates the mold 2 at a high speed. Meanwhile, the belt material fluid F is solidified. And
By peeling this from the mold 2, the endless belt 1 as shown in FIG. 5 can be obtained. The endless belt 1 has protrusions protruding from the "belt outer peripheral surface" so as to extend in the belt circumferential direction near both ends in the belt width direction. When the endless belt 1 is turned upside down as shown in the drawing, the "belt outer peripheral surface", which had the protruding portions near both ends until then, is changed to the "belt inner peripheral surface", and these protruding portions are prevented from slipping. It can function as a part. That is, the endless belt 1 shown in FIG. 1 can be obtained by inverting the endless belt after demolding. In addition, when the endless belt 1 is not sold by incorporating it into a belt driving device or an image forming apparatus but is sold by itself, the endless belt 1 is shipped only after the process before the front and back is reversed, and the front and back reversing work is performed by the user. You may get it. In this case, the manufacturing cost of the endless belt 1 can be reduced by omitting the front and back reversing work. Also, when shipping after turning the inside out,
It is possible to avoid a situation in which the user is forced to reverse the work.

In FIG. 3 described above, when the discharge nozzle 3 is controlled so that the amount of the belt material fluid F supplied in the horizontal direction is constant, the tip of the discharge nozzle 3 faces the groove-shaped recess 2b. At the position, the supply amount of the belt material fluid F is insufficient by the volume of the recess. And
As a result, the shape of the endless belt 1 near its both ends may be abnormal, or the thickness of the endless belt 1 may be made thinner than the normal value when the belt material fluid F having a relatively low viscosity is used. Therefore, with respect to the position of the groove-shaped recess 2b on the inner peripheral surface of the mold 2, it is desirable to supply a larger amount of the belt material fluid F by the discharge nozzle than at other positions. As a method for realizing such supply, a method of increasing the amount of belt material fluid fed per unit time from the feeding means to the discharge nozzle 3 only when the tip of the discharge nozzle 3 is opposed to the groove-shaped recess 2b. Can be considered. Further, instead of increasing the belt material fluid feeding amount, the horizontal movement of the discharge nozzle 3 may be temporarily stopped or decelerated at the facing position. Further, the belt material fluid F may be supplied by the constant velocity movement of the discharge nozzle 3, and then the belt material fluid may be re-supplied only at the position of the groove-shaped recess 2b. Further, the belt material fluid F having a higher material solid content concentration may be supplied at the facing position. However, in this case, a plurality of types of belt material fluids F containing the same material and different in material solid content concentration are prepared, and the material solid content concentration of the belt material fluid F supplied from the discharge nozzle 3 is set to the above flow rate. It is necessary to change it by switching at the road switching means.

When manufacturing the multi-layered endless belt 1, the endless belt film formed first on the inner peripheral surface of the mold 2 is the lower layer having the detent guide portions (1a) near both ends. Therefore, it is necessary to first form the endless belt film using the belt material fluid for the lower layer, and then sequentially stack the endless belt film toward the surface layer thereon.

When the belt width is adjusted by cutting both ends or one end of the endless belt 1 after molding, as shown in FIG. 2, the dam member 2 is located outside the groove-shaped recess 2b.
It is desirable to dispose a or to supply the belt material fluid in an amount that can spread to the outside of the groove-shaped recess 2b if the dam member 2a is not provided. This is because it is possible to secure a margin in which the anti-slip guide portions (1a) are not formed at both ends of the endless belt 1 after molding. If the belt width is not adjusted by cutting, the groove-shaped recess 2b is formed so that the offset prevention guide portions (1a) are formed exactly at both ends of the molded endless belt 1.
May be provided near the dam member 2a.

Although the endless belt in which the detent guide portions 1a are provided near both ends has been described with reference to FIG. 1 described above, it may be provided at either one end or only near the end. In this case, the mold 2 provided with only one groove-shaped recess 2b may be used.

As shown in FIG. 6, it is desirable that the groove-shaped recess 2b has an opening width x larger than the groove bottom width y. With this configuration, when the endless belt film obtained by solidifying the belt material fluid F is peeled from the mold 2, the detent guide portion (1a) formed in the groove-shaped recess 2b is hooked on the inner wall of the recess. This is because the endless belt film can be satisfactorily peeled off.

Since an endless belt 1 used as an intermediate transfer belt in an electrophotographic image forming apparatus generally has a transfer bias applied to form a transfer electric field,
It is required to exert an appropriate electric resistance. As such endless belt 1, polyethylene (high density, medium density,
Low density, linear low density), propylene ethylene block or random copolymer, rubber or latex component such as ethylene / propylene copolymer rubber, styrene / butadiene rubber, styrene / butadiene / styrene block copolymer or Hydrogenated derivative, polybutadiene, polyisobutylene, polyamide, polyamideimide, polyacetal, polyarylate, polycarbonate, polyphenylene ether, modified polyphenylene ether, polyimide, liquid crystalline polyester, polyethylene terephthalate, polysulfone, polyethersulfone, polyphenylene sulfide, polybisamide triazole , Polybutylene terephthalate, polyetherimide, polyetheretherketone, acrylic, polyvinylidene fluoride Den, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene, fluororubber, acrylic Acid alkyl ester copolymer, polyester ester copolymer, polyether ester copolymer, polyether amide copolymer,
An olefin copolymer, a polyurethane copolymer, or a mixture thereof, particularly polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene Examples thereof include copolymers, tetrafluoroethylene perfluoroalkyl vinyl ether copolymers, polytetrafluoroethylene, and other fluororesins and fluororubbers to which a conductive filler is added to adjust electrical resistance. Also, acrylonitrile-butadiene rubber (NBR), styrene butadiene rubber, butadiene rubber, ethylene propylene rubber, chloroprene on a metal or alloy belt of aluminum, iron, copper, stainless steel or the like, or a conductive resin belt in which carbon or metal particles are dispersed. Conductive materials such as rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, acrylic rubber, fluororubber and urethane rubber are carbon (Ketjen black), graphite, carbon fiber, metal powder, conductive metal oxide, organic It may be a laminate of elastic layers in which metal oxides, organic metal compounds, organic metal salts, conductive polymers, etc. are dispersed to control the volume resistivity. Further, a surface release layer coated with a fluororesin such as PFA or FEP, if necessary, or a layer formed integrally with the anti-slip guide part of polyurethane rubber having a lower electric resistance by adding a conductive filler to the lowermost layer. It may be provided. The electric resistance value of the endless belt 1 when used as an intermediate transfer belt should be set in the range of 10 ⁶ to 10 ¹⁰ [Ω · cm (when 1 kV is applied)] by adjusting the dispersion amount of a conductive material such as carbon. Is desirable.

As a resin used for the intermediate transfer belt, a resin such as a fluorine resin, a polycarbonate resin, a polyimide resin or the like, which has a poor elasticity, has been conventionally used. However, in recent years, an intermediate transfer belt in which all layers or a part of the layers of the intermediate transfer belt are made of a material having excellent elasticity has been used. This is for the reason explained below. That is, in the full-color image forming apparatus, the intermediate transfer belt made of a resin having poor elasticity is yellow,
Excessive pressure is applied at the transfer nip to the four-color toner image in which the toner images of magenta, cyan, and black are laminated to facilitate aggregation of individual toner particles. And
This is because an excessive agglomeration of the toner particles easily causes a defective image such as a hollow image or a missing edge of the image. Further, in recent years, there has been an increasing demand for transferring a full-color image not only to general paper such as transfer paper, but also to a transfer member having poor surface smoothness such as Japanese paper or paper with uneven decoration. Such a transfer body is liable to cause a gap between the transfer body and the toner at the time of transfer, and a transfer failure is likely to occur due to poor adhesion. If the transfer pressure is increased in order to suppress the poor adhesion, the toner particles are excessively aggregated to cause the hollow image and the missing edge of the image. Therefore, by using a material having excellent elasticity for the intermediate transfer belt, the surface of the intermediate transfer belt can be flexibly deformed by following the unevenness of the toner image even with a relatively low transfer pressure. Examples of such a material include elastic rubber and thermoplastic elastomer. Furthermore, as elastic rubber and thermoplastic elastomer,
Butyl rubber, fluorine rubber, acrylic rubber, EPDM,
NBR, acrylonitrile-butadiene-styrene rubber natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic Tic 1,2-polybutadiene, epichlorohydrin type rubber, recone rubber, fluororubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber, thermoplastic elastomer (for example, polystyrene type, polyolefin type, polyvinyl chloride type, polyurethane type) , One type or a mixture of two or more types selected from the group consisting of polyamide type, polyurea, polyester type and fluororesin type (7)). When these materials are used, even if the transfer pressure at the transfer nip is kept relatively low, the surface of the intermediate transfer belt can be flexibly deformed by following the irregularities of the toner image. Thus, even if a transfer body having a poor planar smoothness is used, it is possible to form an image with no voids or edges.

In the intermediate transfer belt provided with the elastic layer and the surface layer for improving the separation of the toner from the belt at the time of two transfers, the transfer nip having a sufficient width is formed, and the toner image and the photosensitive drum are formed. It is desirable that the thickness of the elastic layer is 0.1 to 5 [mm] from the viewpoint of flexibly deforming by following a step between the elastic layer and the like and suppressing the material cost. In addition, the surface layer is preferably as thin as possible so that it can be deformed to some extent by following the deformation of the lower elastic layer.
[Μm] is preferable.

Endless belt 1 used as a photoreceptor belt as a latent image carrier in an electrophotographic image forming apparatus.
Also in the case of manufacturing, the belt needs to exhibit sufficient conductivity. Therefore, it is desirable to use the same material as the intermediate transfer belt as a raw material. However, it is necessary to laminate the photosensitive layer on the layer made of this material. When the anti-slip guide portion is located on the inner peripheral surface of the belt, it is desirable to perform this lamination after reversing the endless belt (precursor of the photosensitive belt) after demolding. In general, a non-elastic material or a material with extremely poor elasticity is used for the photosensitive layer, so if the layers are turned upside down after stacking, cracks or creases are likely to occur due to deformation at that time, and deterioration may easily occur. Because. Therefore, it is preferable to form the photosensitive layer on the belt film formed with the anti-slip guide portion by centrifugal molding and then remove the mold from the belt film by a suitable method such as a dip coating method or a spray coating method. However, this is not the case when the running guide of the belt is guided by locating the detent guide portions near both ends of the belt outer peripheral surface and abutting the guide rollers on the belt outer peripheral surface portion between both guide portions.

As the photosensitive layer, there are a single layer type including one layer and a laminated type in which a plurality of layers are laminated. The laminated type is a charge generating layer containing a charge generating substance and the generated charge is exposed to light. And a charge transport layer that moves to the surface of the layer. This charge generation layer is a layer containing a charge generation substance as a main component, and a binder resin is contained as necessary. The charge generating substance may be either an inorganic material or an organic material.

For example, as the charge generating substance made of an inorganic material, crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, amorphous silicon and the like can be mentioned. The amorphous silicon is preferably dangling bonds terminated with hydrogen atoms or halogen atoms, or doped with boron atoms or phosphorus atoms.

Further, for example, as the charge generating substance made of an organic material, a phthalocyanine pigment such as a metal phthalocyanine or a metal-free phthalocyanine, an azurenium salt pigment, a squaric acid methine pigment, an azo pigment having a carbazole skeleton, and triphenyl. Azo pigments having amine skeleton, azo pigments having diphenylamine skeleton, azo pigments having dibenzothiophene skeleton, azo pigments having fluorenone skeleton, azo pigments having oxadiazol skeleton, azo pigments having bisstilbene skeleton, distyryl oxadiazo -Azo pigment having a skeleton, an azo pigment having a distyrylcarbazole skeleton, a perylene pigment,
Examples thereof include anthraquinone-based or polycyclic quinone-based pigments, quinoneimine-based pigments, diphenylmethane and triphenylmethane-based pigments, benzoquinone and naphthoquinone-based pigments, cyanine and azomethine-based pigments, indigoid-based pigments and bisbenzimidazole-based pigments. The inorganic materials and organic materials listed above can be used alone or as a mixture of two or more kinds.

The binder resin that may be contained in the charge generation layer as required includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyra. , Polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole,
Examples thereof include polyacrylamide. These binder resins can also be used alone or as a mixture of two or more kinds. In addition, a low molecular weight charge transport material may be added if necessary.

Charge transport materials that can be used in combination with the charge generation layer include electron transport materials and hole transport materials. Examples of electron-transporting substances include chloroanil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4. 5,7-Tetranitroxanthone, 2,4,8-Trinitrothioxanthone, 2,6,8-Trinitro-4H-indeno [1,2
-B] Examples include electron-accepting substances such as thiophen-4-one and 1,3,7-trinitrodibenzothiophene-5,5-dioxide. These can be used alone or as a mixture of two or more kinds. on the other hand,
Examples of the hole transport material include oxazole derivatives, oxadiazol derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl). ) Propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives and the like. To be These can also be used alone or as a mixture of two or more kinds.

The charge generating layer contains a charge generating substance, a solvent and a binder resin as main components, and includes any additives such as a sensitizer, a dispersant, a surfactant and a silicone oil. It may be. Methods for forming the charge generation layer include a vacuum thin film forming method and a casting method from a solution dispersion system. In the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method,
A reactive sputtering method, a CVD method, or the like is used, and the thin film made of the above-described inorganic material or organic material is favorably formed. Further, in the casting method, the charge generating substance made of the above-mentioned inorganic or organic material is added with tetrahydrofuran, cyclohexanone, dioxane, if necessary.
A charge generation layer can be formed by dispersing a solvent such as dichloroethane or butanone together with a binder resin with a ball mill, an attritor, a sand mill or the like, and diluting the dispersion liquid appropriately and coating the dispersion liquid. The dispersion liquid can be applied by a dip coating method, a spray coating method, a bead coating method, or the like. The thickness of the charge generation layer is preferably about 0.01 to 5 [μm], and more preferably 0.05 to 2 [μm].

The charge transport layer can be formed by dissolving or dispersing a mixture or copolymer containing a charge transport component and a binder component as main components in a suitable solvent, and coating and drying the mixture. For its thickness,
About 10 to 100 [μm] is suitable, and when high resolution is required, about 10 to 30 [μm] is desirable. Further, as the polymer compound which can be used as the binder component, polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride / acetic acid Vinyl copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal,
Polyvinyl toluene, acrylic resin, silicone resin,
Examples thereof include thermoplastic or thermosetting resins such as fluororesins, epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins. These polymer compounds can be used alone or as a mixture of two or more kinds, or can be used as a copolymerized product with a charge transport material. In addition, examples of the material that can be used as the charge transport material include the above-mentioned low-molecular-weight electron transport material and hole transport material. The amount of the charge transport material used is preferably 20 to 200 parts by weight, more preferably about 50 to 100 parts by weight, based on 100 parts by weight of the polymer compound. Dispersing solvents that can be used when preparing the charge transport layer coating solution include methyl ethyl ketone, acetone,
Examples include ketones such as methyl isobutyl ketone and cyclohexanone, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, esters such as ethyl acetate and butyl acetate. To be Further, when the charge transport layer is the surface layer of the photoreceptor belt, a filler material may be contained in the surface portion of the charge transport layer. The filler material may be organic or inorganic. Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, and a-carbon powder. Further, as the inorganic filler material, metal powder such as copper, tin, aluminum and indium, silica, tin oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide,
Examples thereof include tin oxide doped with antimony, metal oxides such as indium oxide doped with tin, metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, potassium titanate, and boron nitride. . From the viewpoint of improving wear resistance, it is advantageous to use an inorganic filler material having high hardness. Particularly, silica, titanium oxide, and alumina are effective.

These organic or inorganic filler materials can be used alone or in admixture of two or more. Further, it can be dispersed together with the charge transport substance, the binder resin, the solvent and the like by using an appropriate disperser. The average primary particle size of the filler particles is preferably 0.01 to 1.0 [μm], and is 0.05 to 0.5 [from the viewpoint of the transmittance and wear resistance of the charge transport layer. μ
m] is desirable. Although it is possible to include a filler material in the entire charge transport layer, there are cases where the exposed portion potential becomes high. Therefore, a filler concentration gradient that reduces the filler content from the surface to the back side of the charge transport layer may be provided, or the charge transport layer may be a plurality of layers having different filler content rates and similar filler concentration gradients may be provided. Is desirable. A leveling agent may be added for the purpose of reducing irregularities (thickness variations) generated in the charge transport layer. As the leveling agent, a silicone oil-based leveling agent, which can impart a high level of smoothness with a small amount and has a small influence on electrostatic properties, is particularly preferable. Such silicone oil-based leveling agents include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen polysiloxane, cyclic dimethyl polysiloxane, alkyl-modified silicone oil, polyether-modified silicone oil,
Alcohol-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil,
Examples thereof include carboxyl-modified silicone oil, higher fatty acid-modified silicone oil, and higher fatty acid-containing silicone oil. The thickness of the charge transport layer is 5 to 50.
[Μm] is good, and more preferably 10 to 30 [μm]. In recent years, there is a tendency to reduce the thickness of the charge transport layer in order to achieve high image quality and high resolution.

If necessary, an undercoat layer may be provided between the conductive support and the photosensitive layer by a solution coating method.
This undercoat layer is provided for the purpose of improving the adhesiveness, suppressing the generation of moire images, improving the coatability of the photosensitive layer, and reducing the residual potential. A resin is generally used as the main component of the undercoat layer, but since an organic solvent is applied when the photosensitive layers are laminated, it is desirable to use a resin that exhibits excellent solubility resistance in the organic solvent. Such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymerized nylon,
Alcohol-soluble resin such as methoxymethylated nylon,
Examples thereof include polyurethane, melamine resin, alkyd-melamine resin, epoxy resin, and curable resin forming a three-dimensional network structure. Further, metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide and indium oxide, or fine powders such as metal sulfides and metal nitrides may be dispersed. Further, a metal oxide layer formed by a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent or the like may be used as the undercoat layer. Further, Al ₂ O ₃ is deposited by an anodic oxidation method, an organic substance such as polyparaxylylene (parylene), SnO ₂ , TiO ₂ , or IT.
The undercoat layer may be provided by depositing an inorganic substance such as O or CeO ₂ by a vacuum thin film forming method. The thickness of the undercoat layer is suitably 0.1 to 20 [μm], preferably 1 to 10 [μm].

A protective layer may be provided on the photosensitive layer. Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, Polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-
Examples thereof include resins such as styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. Generally, a filler material is added to the protective layer, and the same materials as those described above are used alone or in combination of two or more, and a ball mill, an attritor, a sand mill, a charge transport material, a binder resin, a solvent, etc. are used together. It may be dispersed by ultrasonic waves. The primary particle size of the filler is preferably 0.01 to 0.8 [μm] from the viewpoint of the transmittance and wear resistance of the protective layer. In addition, the image quality can be improved by adding the same material as the charge transport material used for the charge transport layer to the protective layer. The protective layer can be formed by dip coating, spray coating, beat coating,
A nozzle coat, a spinner coat, a ring coat, etc. are mentioned. The thickness of the protective layer is 0.1 to 10 [μ
m] is suitable.

An intermediate layer may be provided between the photosensitive layer and the protective layer on the surface side of the photosensitive layer for the purpose of controlling the charge injection amount. A binder resin is generally used as a main component in the intermediate layer. Examples of the binder resin include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. Examples of the method for forming the intermediate layer include a coating method. The thickness of the intermediate layer is 0.
About 05 to 2 [μm] is suitable.

The protective layer, the intermediate layer, the photosensitive layer (charge transport layer, charge generating layer) and the subbing layer are provided with an antioxidant, a plasticizer, a lubricant, an ultraviolet ray for the purpose of suppressing a decrease in sensitivity and an increase in residual potential. An absorber and a low molecular weight charge transport material may be added. Examples of typical materials for these compounds are described below. However,
It is not limited to these. 1. Examples of antioxidants (a) phenolic compound 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylpheno- N-octadecyl-3- (4'-hydroxy
-3 ', 5'-di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol),
2,2'-methylene-bis- (4-ethyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-butylphenol), 4,4'-butylidenebis -(3-methyl-6-t-butylphenol),
1,1,3-tris- (2-methyl-4-hydroxy-
5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-
4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3.
3′-bis (4′-hydroxy-3′-t-butylphenyl) butyric acid) crycol ester, tocopherols and the like. (B) Para-phenylenediamines N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-
Phenylenediamine, N, N'-di-isopropyl-p
-Phenylenediamine, N, N'-dimethyl-N, N'-
Di-t-butyl-p-phenylenediamine and the like. (C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t
-Octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like. (D) Organic sulfur compounds dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate and the like. (E) Organophosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like. 2. Examples of plasticizer (a) Phosphate ester plasticizer triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-phosphate 2-ethylhexyl, triphenyl phosphate, etc. (B) Phthalate ester plasticizers dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate. Acid dinonyl, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butylbenzyl phthalate, butyllauryl phthalate, methyloleyl phthalate, octyldecyl phthalate, dibutyl fumarate, dioctyl fumarate Such. (C) Aromatic carboxylic acid ester-based plasticizer trioctyl trimellitate, tri-n trimellitate
-Octyl, octyl oxybenzoate and the like. (D) Aliphatic dibasic acid ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-adipate
Octyl, adipic acid-n-octyl-n-decyl, diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate,
Diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2-ethoxyethyl sebacate, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, dihydrotetrahydrophthalate -N-octyl and the like. (E) Fatty acid ester derivative butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester,
Triacetin, tributyrin, etc. (F) Oxyester plasticizers such as methyl acetylricinoleate, butyl acetylricinoleate, butylphthalylbutyl glycolate, and tributyl acetylcitrate. (G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, epoxy butyl stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. . (H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate. (I) Chlorine-containing plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl, etc. (J) Polyester plasticizer polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like. (K) Sulfonic acid derivative p-toluene sulfonamide, o-toluene sulfonamide, p-toluene sulfone ethylamide, o-toluene sulfone ethylamide, toluene sulfone-N-ethylamide, p-toluene sulfone-N-cyclohexylamide and the like. (L) Citric acid derivative triethyl citrate, acetyl triethyl citrate, tributyl citrate, tributyl acetyl citrate, tri-2-ethylhexyl acetyl citrate, acetyl citrate-n-octyl decyl and the like. (M) Other terphenyls, partially hydrogenated terphenyls, camphor, 2
-Nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like. 3. Examples of lubricants (a) Hydrocarbon compounds Liquid paraffin, paraffin wax, microwax, low-polymerization polyethylene, etc. (B) Fatty acid compound lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like. (C) Fatty acid amide compounds Stearyl amide, palmityl amide, olein amide, methylene bis stearamide, ethylene bis stearamide and the like. (D) Ester compound Lower alcohol ester of fatty acid, polyhydric alcohol ester of fatty acid, fatty acid polyglycol ester and the like. (E) Alcohol-based compounds cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like. (F) Metal soaps Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like. (G) Natural wax carnauba wax, candelilla wax, beeswax, whale wax, ivorot wax, montan wax and the like. (H) Other silicone compounds, fluorine compounds and the like. 4. Examples of ultraviolet absorber (a) Benzophenone-based 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2 '-Dihydroxy 4-methoxybenzophenone and the like. (B) Salsylate-based phenyl salicylate, 2,4 di-t-butylphenyl 3,5-di-t-butyl 4-hydroxybenzoate and the like. (C) benzotriazole-based (2′-hydroxyphenyl) benzotriazole,
(2'-hydroxy5'-methylphenyl) benzotriazole, (2'-hydroxy5'-methylphenyl) benzotriazole, (2'-hydroxy3'-tert-butyl5'-methylphenyl) 5-chlorobenzotriazole (D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy 3 (paramethoxy) acrylate and the like. (E) Quencher (metal complex salt system) Nickel (2,2 ′ thiobis (4-t-octyl) phenolate) n-butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like. (F) HALS (hindered amine) bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2 -[3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] ethyl] -4- [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpyridine,
8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine and the like.

In the case of manufacturing the endless belt 1 used as a transfer body transport belt for transporting a transfer body such as a transfer paper in an electrophotographic image forming apparatus, carbon, metal particles, metal oxide, etc. are dispersed. It is desirable to use a conductive resin as the belt material fluid. This is because, in general, a voltage is applied to the transfer body transport belt, which electrostatically attracts the transfer body and can prevent the transfer body from being displaced, causing image distortion due to the displacement, and wrinkles.

When the endless belt shown in FIG. 1 is used as a fixing belt for carrying a transfer member on which a toner image is heated and fixed in an electrophotographic image forming apparatus,
It is desirable to use a heat-resistant resin material such as polyimide, polyamide, or polyester. This is to avoid deterioration due to the effect of heating during fixing.

Next, as an image forming apparatus to which the present invention is applied, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described. FIG. 7 is a schematic configuration diagram of the printer according to the present embodiment. In the figure, the photosensitive drum 10, which is a latent image carrier, is driven to rotate counterclockwise in the figure, while its surface is uniformly charged by a charging charger 11 using a corotron, a scorotron, or the like, and then a laser optical device (not shown) is used. It receives the scanning of the laser beam L emitted from the device and carries an electrostatic latent image. This scanning is performed on the basis of monochromatic image information obtained by decomposing a full-color image into yellow, magenta, cyan, and black color information. Therefore, the electrostatic latent image of yellow, magenta, cyan, or black is formed on the photosensitive drum 10. A latent image is formed. A revolver developing unit 12 is arranged on the left side of the photosensitive drum 10 in the figure. This has a yellow developing device 12Y, a magenta developing device 12M, a cyan developing device 12C, and a black developing device Bk in a rotating drum-shaped housing, and each developing device faces the photosensitive drum 10 by rotation. Sequentially move to the developing position. The yellow developing device 12Y, the magenta developing device 12M, the cyan developing device 12C, and the black developing device Bk are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. Electrostatic latent images for yellow, magenta, cyan, and black are sequentially formed on the photoconductor drum 10, and these are sequentially developed by the developing devices of the revolver developing unit 12 to form a yellow toner image, a magenta toner image, and a cyan image. Toner image,
It becomes a black toner image.

An intermediate transfer unit 13 is arranged downstream of the developing position in the rotation of the photosensitive drum 10.
This is a tension roller 13a, an intermediate transfer bias roller 13b as a transfer means, and a secondary transfer backup roller 13
c. The intermediate transfer belt 13e stretched by the belt driving roller 13d is endlessly moved clockwise in the figure by the rotational driving of the belt driving roller 13d. The yellow toner image, the magenta toner image, the cyan toner image, and the black toner image developed on the photoconductor drum 10 enter the intermediate transfer nip where the photoconductor drum 10 and the intermediate transfer belt 13e contact each other. Then, while being influenced by the bias from the intermediate transfer bias roller 13b, the intermediate transfer is performed by superimposing on the intermediate transfer belt 13e to form a four-color superimposed toner image.

The surface of the photosensitive drum 10 that has passed through the intermediate transfer nip as the drum rotates rotates the drum cleaning unit 1.
The transfer residual toner is cleaned by 7. The cleaning unit 17 is for cleaning the transfer residual toner by a cleaning roller to which a cleaning bias is applied, but may be a cleaning brush such as a fur brush or a magfur brush, or a cleaning blade.

The surface of the photosensitive drum 10 from which the transfer residual toner has been cleaned is discharged by the discharging lamp 18. As the static elimination lamp 18, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL) or the like is used. A semiconductor laser is used as the light source of the laser optical device. With respect to the emitted light, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter may be used only in a desired wavelength range.

A first paper carrying unit 14 is provided on the lower side of the intermediate transfer unit 13 in the figure, and a second paper carrying unit 15 and a fixing unit 16 are provided on the left side of the figure. ing. The first paper transport unit 14 includes a belt drive roller 14a, driven rollers 14b and 14c, and a first paper transport belt 14e stretched by a secondary transfer bias roller 14d serving as a transfer unit.
It is moved endlessly counterclockwise in the figure by the rotation drive of. Further, it is configured to move in the vertical direction in the figure by a moving unit (not shown), and at least one color toner image (yellow toner image) on the intermediate transfer belt 13e or 2
When the color or three-color superimposed toner image passes through the position facing the secondary transfer bias roller 14d, the toner image moves to a position where it does not contact the intermediate transfer belt 13e. And
Before the leading edge of the four-color superimposed toner image on the intermediate transfer belt 13e enters the position facing the secondary transfer bias roller 14d, it moves to the contact position with the intermediate transfer belt 13e and moves through the secondary transfer nip. Form.

On the other hand, the registration roller pair 19 which sandwiches the transfer paper P sent from a paper feed cassette (not shown) between the two rollers is used as the intermediate transfer belt 13e.
The toner image is fed toward the secondary transfer nip at a timing when it can be superimposed on the upper four-color superimposed toner image. The four-color superimposed toner image on the intermediate transfer belt 13e is secondarily transferred onto the transfer paper P collectively under the influence of the secondary transfer bias from the secondary transfer bias roller 14d in the secondary transfer nip. . By this secondary transfer, a full color image is formed on the transfer paper P.

The transfer paper P on which a full-color image is formed is
It is sent to the second paper transport unit 15 by the first paper transport belt 14e of the first paper transport unit 14. Drive roller 1
The second paper transporting unit 15 for moving the second paper transporting belt 15c stretched by the 5a and the driven roller 15b endlessly in the counterclockwise direction in the figure by the rotational driving of the drive roller 15a is provided from the first paper transporting unit 14. The received transfer paper P is sent into the fixing device 16.

The fixing device 16 conveys the fed transfer paper P while sandwiching it in the fixing nip formed by the contact between the heating roller 16a and the backup roller 16b. The full-color image on the transfer paper P is heated by the heating roller 16a.
It is fixed on the transfer paper P under the influence of heating from the sheet and the pressure applied in the fixing nip.

Although not shown, the transfer paper P is attached to the first paper carrying belt 14e and the second paper carrying belt 15c.
A bias for adsorbing is applied. Also,
A paper discharging charger for discharging the transfer paper P and three belt discharging chargers for discharging each belt (the intermediate transfer belt 13e, the first paper carrying belt 14e, and the second paper carrying belt 15c) are provided. In addition, the intermediate transfer unit 13
Also includes a belt cleaning unit having the same configuration as the drum cleaning unit 17, which cleans the transfer residual toner on the intermediate transfer belt 13e. Further, the intermediate transfer belt 13e is also provided with an application unit for applying zinc stearate to make the friction coefficient of the surface thereof lower than that of the transfer paper P.
The secondary transferability of the color superposed toner image is improved.
The coefficient of friction of the transfer paper P is usually 0.35 though it depends on the kind of paper.
Is about 0.7, the friction coefficient of the surface of the intermediate transfer belt 13e coated with zinc stearate is 0.1.
5 to 0.3.

In the printer having the above-described structure, the endless belt 1 shown in FIG. 1 is provided as the intermediate transfer belt 13e, the first paper carrying belt 14e, and the second paper carrying belt 15c. At the time of intermediate transfer, the intermediate transfer belt 1
If 3e is run to one side, there is a risk that the intermediate transfer belt 13e and the photosensitive drum 10 may rub against each other at the intermediate transfer nip to disturb the intermediate transfer toner image. At the secondary transfer nip, the intermediate transfer belt 13e and the first paper transport belt 1
There is also a risk of rubbing the transfer sheet P on the sheet 4e and disturbing the full-color image. However, in this printer, since the offset prevention guide portion of the intermediate transfer belt 13e is integrated with the belt main body, it is not peeled off or displaced. Therefore, it is possible to eliminate the disturbance of the intermediate transfer toner image (on the intermediate transfer belt) and the full-color image (on the transfer paper P) due to the peeling and the deviation. Also,
The offset running of the first paper transport belt 14e also causes disturbance of the full-color image at the secondary transfer nip, but since this printer also uses the endless belt of FIG. 1 as the first paper transport belt, such disturbance is eliminated. can do. Furthermore, if the second paper transport belt 15c is run to one side, the transfer paper P cannot be fed into the fixing device 16, which may cause a jam. However, in the present printer, since the endless belt of FIG. 1 is also used as the second paper conveyance belt 15c, it is possible to eliminate the jam caused by the peeling or the deviation of the offset guide of the second paper conveyance belt 15c.

In this printer, the photosensitive drum 10 is provided as a latent image carrier, but a photosensitive belt having a photosensitive layer on its surface may be used. However, if the photoconductor belt is run while being offset during the intermediate transfer, there is a risk that the photoconductor belt and the intermediate transfer belt, which is a transfer body, may rub against each other to disturb the intermediate transfer toner image. Therefore, the endless belt shown in FIG. 1 may be used as the photosensitive belt. By doing so, it is possible to eliminate the disturbance of the intermediate transfer toner image due to the peeling or displacement of the offset guide of the photosensitive belt.

Further, in this printer, as shown in FIG. 7, the second paper transport unit 15 and the fixing device 16 are separate bodies, but they may be integrated as shown in FIG. . In this case, the second paper transport belt 15c functions as a fixing belt, and since heat from the heating roller 16a is directly transmitted to this, use a material having excellent heat resistance such as polyimide. Is desirable. In FIG. 8, the transfer paper P before being sandwiched in the fixing nip between the heating roller 16a and the backup roller 16b has the full-color image held therein as unfixed. Therefore, when the second paper transport belt 15 runs to one side and rubs against the heating roller 16a, the full-color image is disturbed. Therefore, it is desirable to use the endless belt shown in FIG. 1 as the second paper conveying belt 15c also in the paper conveying and fixing unit shown in FIG. By doing so, it is possible to eliminate the disturbance of the full-color image due to the peeling or misalignment of the deviation prevention guide of the second paper transport belt 15c (fixing belt).

FIG. 9 shows a modified apparatus of the printer according to this embodiment. This modified apparatus is a so-called tandem type printer, and does not share the photoconductor drum 10 with each color, but rather the photoconductor drums 10Y and 10Y for each color.
It is equipped with M, 10C and 10Bk. Further, the drum cleaning unit 17, the static elimination lamp 18, and the charging roller 20 for uniformly charging the drum are also provided for each color. Although the printer shown in FIG. 7 is provided with the charging charger 11 as the drum uniform charging means, this printer is provided with the charging roller 20.

Also in the printer having such a configuration, the endless belts shown in FIG. 1 are used as the intermediate transfer belt 13e, the first paper carrying belt 14e, and the second paper carrying belt 15c, and the offset guides are peeled off. It is possible to eliminate the disturbance of the image and the occurrence of jam caused by the displacement.
In this printer, the photosensitive drums 10Y of the respective colors are
Intermediate transfer belt 1 for 10M, 10C, and 10Bk, respectively
Since it is necessary to make contact with 3e, the intermediate transfer belt 13e becomes longer than in the revolver type printer shown in FIG. Therefore, in the intermediate transfer belt 13e used in the tandem type image forming apparatus, it is possible to easily reverse the front and back after centrifugal molding. Further, in the tandem system, since latent images of respective colors can be formed and developed in parallel, the image forming speed can be much higher than that of the revolver system.

Next, examples of printers to which the present invention is applied and comparative examples of printers to which the present invention is not applied will be described. [Example 1] A mold 2 having an inner diameter, a length, a width of the groove-shaped recess, and a depth of the groove-shaped recess of 180, 400, 5, and 3 [mm], respectively, was rotated at a speed of 100 [rpm], The belt material fluid F containing the substances listed below was applied to the inner wall. Polyurethane prepolymer: 100 parts by weight Curing agent (isocyanate): 3 parts by weight Carbon black: 20 parts by weight Dispersant: 3 parts by weight Methyl ethyl ketone (MEK): 500 parts by weight

Then, the rotational speed was increased to 1000 [rpm] and centrifugal molding was performed. Further, the molded film was naturally dried by spraying dry air to obtain an endless belt film having a thickness of 300 [μm]. This was peeled from the mold 2 and turned upside down, and then the surface layer dispersions listed below were applied by dip coating to form a surface layer having a thickness of 5 [μm]. -Polyurethane prepolymer: 100 parts by weight-Curing agent (isocyanate): 3 parts by weight-Polytetrafluoroethylene (PTFE) fine powder powder 50 parts by weight-Dispersant: 4 parts by weight-Methyl ethyl ketone (MEK): 500 parts by weight

The thus obtained product was dried at room temperature and then 1
The tension was stretched under the conditions of 30 [° C.] and 2 hours to obtain an endless belt including an elastic urethane resin layer and a surface layer. Both ends of this endless belt were cut with a cutter to adjust the belt width to 368 [mm]. The endless belt after the width adjustment has the anti-slip guide portion located at a position recessed by about 1 [mm] from the end. This endless belt is set as an intermediate transfer belt on a laser printer (imagio color 4000) manufactured by Ricoh Company,
This was modified so that only the intermediate transfer belt unit could be driven freely, and a continuous drive test was conducted. Then, even if the intermediate transfer belt was continuously driven for 30 days, the anti-slip guide portion was not damaged and the supporting roller was not detached. In addition, when a full-color image was output after the continuous drive test, a slight banding image was seen, but it was at a level where there was no problem in actual use. The banding image is considered to be due to the expansion and contraction of the belt.

Comparative Example 1 An endless belt was manufactured under the same conditions as in Example 1 except that the conventional mold 2 shown in FIG. 10 was used. Using this, a continuous drive test similar to that of Example 1 was carried out. One hour after the start of the drive, the intermediate transfer belt started to run eccentrically, and eventually the support roller was released from the wheels.
It has broken further.

Example 2 After the belt material fluid F was centrifugally molded under the same conditions as in Example 1, the above-mentioned dispersion liquid for surface layer was spray-coated on the inner peripheral surface thereof without peeling off the obtained molding film. Further, this was centrifugally molded. After that, the surface layer dispersion liquid was naturally dried, and then the two-layer molding film was peeled from the mold 2 and turned upside down. Then, tension stretching and both ends were cut in the same procedure as in Example 1 to obtain an endless belt. Using this as an intermediate transfer belt, the same continuous drive test as in Example 1 was conducted. As a result, neither peeling nor deviation of the anti-slip guide portion (of course, increase in meandering width due to these is not recognized), and the intermediate transfer belt was not detached from the support roller. Then, when a full-color image was output after the continuous drive test, a banding image was slightly seen, but it was at a level where there was no problem in actual use.

Comparative Example 2 A non-stop guide member made of urethane rubber having a width of 5 mm and a height of 3 mm was attached to both ends of the inner surface of the endless belt of Comparative Example 1 with an acrylate type adhesive. Using the thus obtained endless belt as an intermediate transfer belt, the same continuous drive test as in Example 1 was performed. Then, the meandering width of the intermediate transfer belt began to increase 7 days after the start of driving, and the detent guide member climbed over the roller and eventually caused the intermediate transfer belt to come off and break. When the anti-slip guide member of the broken intermediate transfer belt was examined, the adhesive surface was partially peeled from the belt body. It is considered that the meandering width started to increase due to such partial peeling of the anti-stop guide member.

[Embodiment 3] The inner diameter, the length, the width of the groove-like recess, and the depth of the groove-like recess are 330, 400, 5, and 3, respectively.
The mold 2 having a diameter of [mm] is rotated at a speed of 100 [rpm], and the same belt material fluid F as that of the first embodiment is applied to the inner wall of the mold 2.
Was applied. Then, centrifugal molding was performed at a rotation speed of 1000 [rpm] to obtain a uniform molded film having a thickness of 50 [μm].
A dispersion containing the substances listed below was spray-coated on the inner peripheral surface of this, and then a PVDF resin layer having a thickness of 150 [μm] was centrifugally molded at a rotation speed of 1000 [rpm]. -Polyvinylidene fluoride (PVDF): 100 parts by weight-Carbon black: 18 parts by weight-Dispersant: 3 parts by weight-Toluene: 400 parts by weight

After the PVDF resin layer is dried at room temperature, the belt material fluid F is injected into the inner peripheral surface of the PVDF resin layer to have a thickness of 1
A urethane resin layer of 00 [μm] was centrifugally molded. Furthermore,
The same dispersion layer for surface layer as in Example 1 was spray-coated on the inner peripheral surface of the urethane resin layer, and a surface layer having a thickness of 5 [μm] was centrifugally molded. The 4-layer structured molding film thus obtained was peeled from the mold 2 and turned upside down, and then tension tension was applied and both ends were cut in the same manner as in Example 1 to obtain a lower layer (urethane resin), a PVDF resin layer, and elasticity. An endless belt composed of a urethane resin layer and a surface layer that exerted the above was obtained. Using this as an intermediate transfer belt of the tandem type printer shown in FIG. 9, a continuous drive test was performed in which only the intermediate transfer unit 13 was freely driven. Then, even if it was continuously driven for 30 days, the anti-slip guide was not damaged and the intermediate transfer belt was not detached from each roller. Also,
When a full-color image was output after the continuous drive test, a good image with no banding image and almost no color misregistration was obtained. It is considered that the banding image did not occur because the PVDF resin layer, which is relatively inferior in elasticity, suppressed expansion and contraction of the belt.

Although the embodiments and examples of the printer for forming a full-color image have been described, it goes without saying that the present invention can be applied to an image forming apparatus for forming a single-color image. Further, the printer that performs the intermediate transfer and the secondary transfer has been described. However, in an image forming apparatus that performs only the primary transfer from a latent image carrier such as a photoconductor to the transfer paper or the like, The endless belt according to the present invention may be used as the conveyor belt that conveys to the transfer nip. Further, the present invention is applicable not only to the image forming apparatus, but also to any belt drive device that moves the endless belt endlessly while supporting the endless belt with a plurality of support members.

As described above, in the endless belt of this embodiment, the anti-slip guide portion as the protruding portion is integrally formed of the same material as the belt main body without a seam, and is peeled off from the belt main body due to deterioration of the adhesive or the like. Since there is no deviation, it is possible to eliminate the deterioration of the deviation prevention function due to the peeling or deviation. Moreover, since the step of fixing the belt body is not necessary, the cost increase due to the execution of the step can be eliminated. In the case of an endless belt using at least one of elastic rubber or thermoplastic elastomer as a material, when it is used as a latent image carrying belt, an intermediate transfer belt, or a conveyor belt that conveys a transfer body to a transfer nip, Even if the transfer pressure is kept relatively low, it is possible to flexibly deform the surface of the toner image by following the irregularities of the toner image. Thus, even if a transfer body having a poor planar smoothness is used, it is possible to form an image with no voids or edges. Further, in the printer of this embodiment, since the offset running due to the peeling or deviation of the offset prevention guide portion of the intermediate transfer belt 13e is eliminated, the intermediate transfer toner image (on the intermediate transfer belt on the intermediate transfer belt ) And the disturbance of the full-color image (on the transfer paper) can be eliminated. Further, when the photoconductor belt using the endless belt according to the embodiment is provided as the latent image carrier, the disturbance of the intermediate transfer toner image caused by the one-sided running of the photoconductor belt can be eliminated. Further, when the conveyance fixing unit shown in FIG. 8 is used, the deviation traveling caused by the peeling or deviation of the deviation prevention guide portion of the second paper conveying belt functioning as a fixing belt is eliminated, so that the deviation traveling is performed. Disturbance of the full-color image before fixing due to the above can be eliminated. Further, in the belt manufacturing method in which centrifugal molding is performed by using the mold 2 shown in FIG. 2, the detent guide portion extending in the belt circumferential direction at or near the end in the belt width direction is made of the same material as the belt main body. Can be integrally molded with. Therefore, it is possible to manufacture an endless belt that eliminates both the deterioration of the offset prevention function due to the peeling and displacement of the offset guide and the increase in cost due to the step of fixing the offset guide. . In addition, if the endless belt film obtained by demolding after centrifugal molding can be used as the endless belt shown in FIG. be able to. Further, as shown in FIG. 6, as the mold 2, if the opening width x of the groove-shaped concave portion 2b is equal to or larger than the groove bottom width y, the groove-shaped groove is formed when the molding film is peeled from the mold 2. The anti-slip guide portion in the recess 2b is not caught on the inner wall of the recess, and the molded film can be easily peeled off.

[0073]

According to the invention of the endless belt of claim 1 or 2, the offset preventing function is lowered due to peeling or deviation of the offset preventing guide, and a step for fixing the offset preventing guide is carried out. There is an excellent effect that both the cost increase due to the above can be eliminated.

According to the invention of the belt driving device of the third aspect, there is an excellent effect that it is possible to eliminate the one-sided running of the endless belt due to the peeling or the deviation of the deviation prevention guide.

According to the invention of the image forming apparatus of claim 4,
There is an excellent effect that it is possible to eliminate the disturbance of the transferred image due to the endless belt being moved one-sidedly due to peeling or deviation of the offset prevention guide.

According to the invention of the image forming apparatus of claim 5,
There is an excellent effect that it is possible to eliminate the disorder of the transferred image caused by the latent image carrying belt being moved to one side due to peeling or deviation of the anti-slip guide.

According to the invention of the image forming apparatus of claim 6,
There is an excellent effect that it is possible to eliminate the image disturbance at the time of fixing which is caused by the endless belt in the fixing means being eccentrically run due to peeling or deviation of the offset guide.

According to the belt manufacturing method of the seventh, the eighth or the ninth aspect of the invention, the deviation preventing function is lowered due to the peeling or deviation of the deviation preventing guide, and the step for fixing the deviation preventing guide is performed. There is an excellent effect that it is possible to manufacture an endless belt that eliminates both cost increase.

[Brief description of drawings]

FIG. 1 is a perspective view showing an endless belt according to the present embodiment.

FIG. 2 is a sectional view showing a mold used for centrifugal molding of the endless belt together with a discharge nozzle.

FIG. 3 is a cross-sectional view showing, together with the mold, the same discharge nozzle that supplies the belt material fluid to the inner surface of the mold.

FIG. 4 is a cross-sectional view showing the mold after the belt material fluid is supplied to the inner surface together with the discharge nozzle.

FIG. 5 is a perspective view showing an endless belt film obtained by peeling from the same mold.

FIG. 6 is an enlarged cross-sectional view showing a groove-shaped recess provided in the same mold.

FIG. 7 is a schematic configuration diagram of a printer according to an embodiment.

FIG. 8 is a configuration diagram showing a modified example of a fixing device and a second paper carrying belt of the printer.

FIG. 9 is a schematic configuration diagram showing a modified device of the printer.

FIG. 10 is a sectional view showing a mold used for conventional centrifugal molding.

FIG. 11 is a schematic diagram illustrating dripping of the end portion of the belt material fluid in the same mold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Endless belt 1a Offset prevention guide part 2 Type 2a Dam member 2b Groove-like recessed part 3 Discharge nozzle 10 Photosensitive drum (latent image carrier) 11 Charger charger 12 Developing device (developing means) 13 Intermediate transfer unit 13b Intermediate transfer bias roller ( Transfer means) 13e Intermediate transfer belt (endless belt) 14 First paper transport unit 14d Secondary transfer bias roller (transfer means) 14e First paper transport belt (endless belt) 15 Second paper transport unit 15c Second paper transport belt ( Endless belt) 16 Fixing device 17 Cleaning unit 18 Discharge lamp 19 Registration roller pair 20 Charging roller P Transfer paper (transfer body) F Belt material fluid

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65H 5/02 B65H 5/02 C 3F049 T 4F213 G03G 15/16 G03G 15/16 15/20 102 15/20 102 21/00 350 21/00 350 // B29K 21:00 B29K 21:00 F Term (reference) 2H033 AA14 BA11 BA12 2H035 CA05 CB06 CF02 CF06 2H071 BA42 DA09 DA12 DA16 DA23 2H200 FA13 GA12 GA23 GA24 GA47 JB07 JB15 JB25 JB43 JB JC04 JC13 JC15 LA25 LC03 MA03 MA14 MA17 3F024 BA01 BA02 BA04 BA05 BA06 CA02 CA05 CB02 DA07 DA17 3F049 BA02 BA11 BB11 LA01 LB03 4F213 AA31 AB19 AG16 WA02 WA03 WA32. WW50

Claims (9)

[Claims] 1. An endless belt in which a projecting portion projecting from the circumferential surface of the belt is provided at or near an end portion in the belt width direction, and the projecting portion is integrally formed of the same material as the belt main body. An endless belt featuring. 2. The endless belt according to claim 1, wherein the raw material contains at least one of elastic rubber and thermoplastic elastomer. 3. A belt drive device for moving an endless belt endlessly while supporting the endless belt on a belt inner peripheral surface by a plurality of supporting members, wherein the endless belt according to claim 1 or 2 is used. Drive. 4. An endless belt for passing a latent image bearing member carrying a latent image, a developing means for developing a latent image on the latent image bearing member, and a position facing the latent image latent image bearing member. An image forming apparatus comprising: An image forming apparatus using the endless belt according to claim 1 or 2. 5. A latent image carrying belt for carrying a latent image while moving endlessly, a developing means for developing the latent image on the latent image carrying belt, and a visible image developed on the latent image carrying belt. In an image forming apparatus including a transfer unit that transfers to a transfer body,
An image forming apparatus comprising the endless belt according to claim 1 or 2 as the latent image carrying belt. 6. A latent image bearing member carrying a latent image, developing means for developing the latent image on the latent image bearing member into a visible image, and a transfer member to which the visible image is transferred. An image forming apparatus having a fixing means for fixing the visible image on the transfer body while being conveyed by a belt, wherein the endless belt is the one according to claim 1 or 2. . 7. A method for producing an endless belt, the endless belt having protrusions protruding from the circumferential surface of the belt, which are provided at or near the ends in the belt width direction by a centrifugal molding method. A method for manufacturing a belt, characterized in that a mold provided with a groove-shaped recess extending in a rotation direction on an inner peripheral surface of the mold is used, and the protrusion is integrally molded with the same material as the belt main body by the groove-shaped recess. . 8. The belt manufacturing method according to claim 7, wherein the endless belt membrane after centrifugal molding is turned upside down. 9. The belt manufacturing method according to claim 7, wherein the mold is used in which the opening width of the groove-shaped recess is equal to or larger than the groove bottom width.